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Pilbara Threadtail (Nososticta pilbara)

The Pilbara threadtail is a small, slender damselfly recorded from the Pilbara of Western Australia, where it occurs in streams and pools. Its aquatic habitat may intersect development works, so crews should check suitable freshwater areas and use precautionary controls. It has DBCA Priority 2 status in Western Australia.

Conservation status

Western Australia, WA Threatened and Priority Fauna List: Priority 2.

Seasonal planning

Seasonal activity, breeding and survey months have not been documented for the Pilbara threadtail. The row below is a general planning window only, not a statement of species activity.

Seasonal information: No species-specific months are recorded.

Month values do not represent known activity levels for this species.

  • Plan habitat checks and survey timing with an ecologist: Planning window only. Species activity and seasonal detectability are not documented; select survey timing with regard to site conditions and project requirements.

Identification: Appearance and size

Use the limited published description as a guide, and seek expert confirmation where identification affects works decisions.

The Pilbara threadtail is a small, slender damselfly, black with orange markings. No measurements are recorded.

Identification: Similar species and field signs

Similar species and diagnostic characters that distinguish the Pilbara threadtail from other local damselflies have not been documented.

Adults are the only species-specific field sign described. No distinctive larval or other field signs are recorded.

  • As general group guidance, damselflies are small and delicate, with wings typically held folded over the back at rest. Confirm identification with a suitable odonate specialist.

Distribution: Known range

Known records indicate a restricted distribution in the Pilbara, but the full range is not established.

The species is known from the Pilbara region of Western Australia. Atlas of Living Australia records show 15 Western Australian records at five distinct 0.1 degree locations, between latitude -21.7 and -21.4 and longitude 116.9 and 117.2. Records outside Western Australia were excluded as likely errors.

Distribution: WA regions and status

DBCA identifies the Pilbara region. The species is DBCA Priority 2, described as poorly known and known from few locations, some on conservation lands. No national listing is given. DBCA priority status is a priority-list category, not a listing under the Biodiversity Conservation Act 2016.

Habitat: Recorded habitat

The species is recorded in freshwater streams and pools.

The Pilbara threadtail inhabits streams and pools. An older Pilbara odonate article describes it hovering above streams in which it breeds.

Habitat: Habitat knowledge

Water permanence, flow conditions, water quality, stream structure, vegetation preferences and the relative importance of pools and streams are not documented. Assess suitable freshwater habitats in the known region rather than assuming absence.

Foraging habitat: Species information

The species' foraging behaviour and habitat have not been documented.

Its diet, prey and foraging habitat have not been documented.

Foraging habitat: General group context

Odonatans are generally daytime predators that catch other insects on the wing. This does not establish the Pilbara threadtail's diet or foraging location.

Breeding habitat: Known information

The species is associated with streams, but its breeding requirements are poorly known.

An older Pilbara odonate article states that the Pilbara threadtail breeds in streams. It is also recorded in streams and pools.

Breeding habitat: Unrecorded details

Eggs, larvae, breeding season, development time, water-flow needs and specific breeding substrates have not been documented.

Sheltering habitat: Known information

Resting and sheltering sites have not been documented.

On still days, the Pilbara threadtail may hover above streams where it breeds. No shelter or resting site is identified.

Sheltering habitat: Precaution

Do not assume that adults are confined to the water's edge or that unoccupied-looking stream margins are unused. Check the stream and adjacent vegetation during field assessment.

Threats: Species-specific threats

Specific threats to the Pilbara threadtail have not been identified.

No species-specific threat assessment or population trend has been documented. Priority 2 status indicates that the species is poorly known and known from few locations.

Threats: Habitat precautions

As a precaution, avoid unnecessary disturbance to streams, pools and their adjacent vegetation where the species may occur. Odonates dependent on permanent running water can be vulnerable to changes in water quality and adjacent vegetation, although this has not been established specifically for the Pilbara threadtail.

Survey methodology: 1. Desktop assessment

Focus survey effort on the freshwater habitats where the species is recorded, while recognising that its detectability is not documented.

Check the works footprint and surrounding area against the known Pilbara record range and DBCA's regional flag. Review available records and habitat mapping, and identify streams, pools and adjacent vegetation for field checking.

Survey methodology: 2. Field inspection

Inspect suitable streams and pools and their margins for adult damselflies. The species has been reported hovering above streams on still days, but no survey season, effort, detection rate or validated survey protocol is documented.

  • Record date, weather, water conditions, search area, observation locations and identification confidence.
  • Photograph suspected individuals where this can be done without disturbance, and arrange expert verification when required.
  • Do not treat a non-detection as evidence of absence, given the limited information on detectability.

Vegetation associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific vegetation association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Ecosystem associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific ecosystem association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Soil and substrate associations

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

No species-specific soil association has been indexed or source-checked in this evidence library. This is an evidence gap, not evidence of no association.

Water and wetland associations: Water-associated habitat mentioned in profile

Source-checked associations and automatically indexed candidates are separated below. An association does not establish site presence, preference or dependence.

The Pilbara threadtail inhabits streams and pools.

Automatically indexed from existing profile text. Not a verified preference, mapped occurrence or habitat requirement. Check the original source and regional qualifiers before use.

Evidence: Unreviewed profile-derived candidate

Confidence: Not independently verified

Region: Scope as described in the quoted profile text; not independently verified. Profile states: WA.

Habitat use: general

Attribution gap: No sentence-level reference is attached to the original profile block. Review the profile bibliography; this candidate is not source-verified.

Fauna records and mapped habitat: Not yet analysed

Record locations can be overlaid with mapping, but record frequency alone does not measure habitat preference. No species is excluded from desktop assessments by this analysis.

No quality-controlled record-to-map analysis has been completed for this species. The existing generalised distribution dots and indicative range polygons have not been treated as precise occurrence coordinates.

A defensible run needs dated, independently attributable records, coordinate uncertainty, duplicate and captive-record checks, layer versions and regional scope. Preference and absence require additional survey-effort and detection evidence.

Habitat limitations and contrary evidence: No supported exclusion recorded

Not recorded is not the same as cannot occur. Low suitability, resident habitat, breeding habitat and occasional movement are different conclusions.

This library has not established a vegetation, ecosystem or soil-type exclusion for this species. This does not mean all habitat is suitable; the evidence needed to justify an exclusion has not been assembled.

Habitat limitations and contrary evidence: Before using a negative association

  • Confirm the taxon, geographic region, life stage and habitat function covered by the evidence.
  • Check survey methods, season, repeated effort and detectability before interpreting non-detection.
  • Investigate credible contradictory records and microhabitats absent from broad mapping.
  • Do not convert a missing map class, low record count or failed data request into species absence.

Before habitat disturbance: 1. Map and assess

Plan works around the limited range information and the reported freshwater habitat.

Map streams, pools and adjacent vegetation within and near the disturbance area. Check whether known records or suitable freshwater habitat occur in the works area, and arrange a suitably timed ecological assessment before clearing.

Before habitat disturbance: 2. Set controls

Where freshwater habitat may be affected, define no-go areas and practical buffers with the project ecologist. Plan to prevent avoidable changes to water quality, flow or adjacent vegetation; no species-specific buffer distances have been published.

During habitat disturbance: 1. Protect habitat

Keep disturbance away from freshwater habitat where practicable and respond cautiously to suspected animals.

Keep vehicles, stockpiles, runoff and clearing activity out of marked streams, pools and retained adjacent vegetation. Follow site controls intended to prevent sediment, contaminants or other avoidable changes entering freshwater areas.

During habitat disturbance: 2. Stop and escalate

If a suspected Pilbara threadtail is found in an area about to be disturbed, pause work in the immediate area and contact the project ecologist or fauna spotter catcher for identification and direction. Do not handle or relocate it unless authorised and appropriately qualified.

After habitat disturbance: 1. Inspect controls

Check that habitat protections remain effective and document any observations or incidents.

Check that exclusion areas, drainage controls and retained streamside vegetation remain intact after works and following relevant site events. Address any observed damage or discharge promptly under the project environmental procedures.

After habitat disturbance: 2. Record and report

Record survey results, suspected observations, identification outcomes and any habitat impacts. Escalate relevant records and incidents through the project environmental and fauna reporting processes.

Rehabilitation actions: 1. Restore site conditions

Rehabilitation should protect or restore freshwater habitat without assuming unrecorded species requirements.

Where rehabilitation is required, stabilise disturbed ground and manage runoff to reduce the chance of sediment or other pollutants entering streams and pools. Retain or restore adjacent vegetation where practicable.

Rehabilitation actions: 2. Monitor outcomes

Monitor rehabilitated areas for erosion, water-quality issues and condition of freshwater habitat. Do not assume that rehabilitation has recreated species habitat without ecological assessment; the sources provide no species-specific restoration criteria.

Sources